The objective of this Project is to systematically study several groups of children who have known auditory processing disorders, or who are at high-risk for such deficits. Behavioral, psychoacoustic, physiologic and electrophysiologic measures will be used to examine hearing sensitivity, cochlear, brainstem and thalamocortical function, binaural processing abilities, and complex listening skills. We will examine children with: 1) early childhood histories of temporary conductive hearing impairment resulting from otitis media with effusion (OME); 2) congenital mild to moderate-severe sensory hearing loss; 3) specific language impairment (SLI); and 4) "paradoxical responses" on neonatal hearing screening measures. Our intent is to study whether: 1) the degree and persistence of the conductive hearing loss associated with OME during infancy and early childhood determines the extent of later peripheral and higher-order auditory dysfunction; 2) the higher-order auditory processing disabilities in children with early-onset cochlear impairments are accounted for by the degree and configuration of their peripheral sensory deficit; 3) children with SLI display higher-order auditory processing problems such as deficits in temporal resolution, binaural processing, and selective listening abilities; and finally, 4) whether infants identified in the neonatal period with abnormal brainstem responses in the presence of normal otoacoustic emissions (a ~paradox~) will persist with these indicators of auditory dysfunction through early childhood and, subsequently, whether they are at risk for communicative disorders. Since auditory deficits may affect one or more portions of the sensory pathway, the results obtained from our psychoacoustic, behavioral, physiologic and electrophysiologic probes of various levels of the system may prove valuable to our understanding the global effects of each of these unique auditory conditions on the child. The comprehensive delineation of auditory function may also serve as the basis for the development of intervention, education, and prevention strategies.